Office furniture and specifically interior space-dividing wall panels are conventionally utilized to divide large open spaces into smaller work areas, commonly referred to as workstations. The wall panels which are interconnected to define the workstations are conventionally provided with a modular electrical system thereon to facilitate the supply of electricity to the various workstations, and hence avoid the necessity of extensive installation of hard electrical wiring to the workstations. These modular electrical systems, which are typically manufactured in the factory and are installed on the panels at the factory or are readily field installed, are commonly provided in a channel-like raceway which extends along the lower edge of the panels, although in some panel systems the electrical system extends at other elevations, such as along the top of the panel or at worksurface (i.e., desk) height.
With the greatly increased usage of numerous types of electrical equipment, including computers, within the office environment, there has been a demand for increased electrical capacity at the various workstations, and at the same time this increased capacity must be able to provide a dedicated or isolated circuit for selected usages such as for computers. To meet this demand, many of the known modular electrical systems as associated with such wall systems have increased the number of available electrical circuits which extend along the wall system, and at present most modular electrical systems available in this industry typically provided three or four electrical circuits, one or more of which may be isolated or dedicated, such as for computer usage. With these known systems, however, the number of workstations and the number of electrical outlets which can be supplied with electricity from a single power source, such as a single floor, wall or ceiling power monument, is limited by the number of available circuits which the system is capable of providing. Further, most of these known and typically available systems do not provide any significant capability for making only selected circuits available at various workstations or locations.
While recent attempts have been made to provide system of the aforementioned type which possesses the capability of increasing the electrical capacity by increasing the number of circuits, nevertheless the known systems of this type have heretofore been structurally and operationally complex in that they have typically required more extensive layout and planning of the system prior to installation of the wall system or prior to mounting of the electrical system thereon, or have increased the number of selectable connection which must be made at the job site which increases the probability of an improper connection being made.
Examples of modular electrical systems used on office furniture, and specifically furniture space-dividing panels, are illustrated in U.S. Pat. Nos. 4,060,294, 4,203,639, 4,370,008, 4,376,561, 4,429,934, 4,781,609, 5,152,698, 5,236,370, 5,252,086, 5,277,609, and 5,318,454.
According to the present invention, there is provided an improved modular electrical system for mounting on furniture components and specifically interior space-dividing wall panels, which electrical system includes modules which each include at least one power block which mounts on the panels and which provide increased electrical circuit capacity, which capacity in the illustrated embodiment is at least six electrical circuits. The power block provides different groupings of circuits which are externally accessible, such as for connection to removable receptacle units, on opposite sides thereof. The grouping of circuits on each side of the power block in the disclosed embodiment includes three circuits. Flexible electrical connectors are provided for connection to and transmitting electrical power between the power blocks of adjacent panels. Each flexible connector transmits only one grouping of electrical circuits therethrough, whereby two such flexible connectors are normally utilized for connection between adjacent power blocks of adjacent main or spine panels to transmit all electrical circuits therebetween. As an alternative, the individual flexible electrical connectors can be used for transmitting electrical energy into branching panels, which branching panels may be provided with only the selected grouping of circuits, rather than all of the circuits associated with the power block of the main panel, whereby two different panel branches can be provided with different groupings of circuits.
In the improved arrangement of the present invention, as aforesaid, the flexible connectors as well as the power blocks and related electrical components associated with the branch panels, which branch panels receive only a selected grouping of three circuits, may be conventional components associated with a standard eight-wire three-circuit system currently sold by the Assignee hereof under the name "The Power Base", which system substantially corresponds to the system disclosed in U.S. Pat. No. 4,781,609. The improved electrical system of this invention can be readily integrated with and used in conjunction with the existing three-circuit Power Base system to facilitate the supplying of electrical power and circuits to an increased number of workstations with greater flexibility while at the same time being compatible so as to permit use of the existing Power Base system, either already in place or newly supplied, thereby providing more efficient and economical utilization of overall equipment while at the same time providing increased flexibility and capability with respect to management of electrical power.
In the improved electrical system of this invention, as aforesaid, power is most conventionally supplied to the system from a floor monument by a base feed assembly. This base feed assembly includes a supply block which mounts on the panel, typically in the raceway between a pair of power blocks which are also mounted on the same panel, and the supply block has a pair of flexible connectors extending therefrom for plug-in connection to at least one of the power blocks. Each flexible power-supply connector transmits therethrough only a selected grouping of circuits, such as three circuits in the illustrated embodiment, so that each connector plugs into a separate terminal on the power block to permit all electrical circuits (six in the illustrated embodiment) to be supplied to the power blocks and hence to the modular electrical system.
As an alternative, the improved power system of this invention, as aforesaid, can utilize a ceiling or top feed assembly for supplying electrical power from a ceiling power source to the electrical system. This ceiling feed system also plugs into one or more terminals on the power block so as to supply all electrical circuits to the modular electrical system.
In the improved electrical system, as aforesaid, the power block is of a compact hollow structure having a height which is significantly greater than its width, and a plurality of electrically conductive plates are supported in insulatively spaced relation, generally vertically spaced relation, within the power block housing. Preferably at least fourteen such conductive plates are supported in a vertically stacked array, and define at least six electrical circuits. The vertically alternate conductive plates have sidewardly projecting contacts which cooperate with the housing to define sidewardly-accessible electrical terminals on opposite sides of the housing for receiving power, for external tap-off of power, and for transfer of power from panel to panel. The terminals accessible from one side of the power block define a first grouping of circuits, typically three circuits. Similarly, the terminals accessible from the other side of the power block define a second grouping of circuits, namely three circuits, with the circuits of the first and second groupings being totally different from one another.